Now, the probability to change the number \(k\)  of agents using strategy A by \(\pm \)  one in each time step can be written as[1]}
\(T^{\pm }(k) = \frac{N-k}{N} \frac{k}{N} \left[1 + e^{\mp \beta [\Pi _A(k) - \Pi _B(k)]}\right]^{-1}.\) 
